Air Barriers/Vapor Barriers/Weather Barriers
1. General: A great introductory article on the function of air barrier systems is available on this page at the Whole Building Design Guide site, which is maintained by the National Institute of Building Sciences.
3. General: The website of the Air Barrier Association of America is an excellent source of technical information and up-to-date code requirements for air barrier systems. All sorts of information is available; the site is well-put-together.
4. Technical: A short article on the function of air barriers and vapor retarders, "Roof Leaks and Air Infiltration" by roof expert Dick Fricklas, is archived on the Buildings.com website. The article is from 2009.